Statistical Database Security

Statistical Database Security

• Statistical databases contain statistical data about various populations.

• A population is a set of tuples of a table that satisfy some selection criteria.

• The statistical database may contain the confidential data about individuals. For example - The database system about government agencies is a statistical database. The statistical database security helps in protecting the sensitive information present in the statistical database from user's access.

• Users are permitted to use some portion of statistical database. He/she can not have access over the complete database system. For instance - In an employees database, any user is not permitted to access the information about employee's salary.

• Statistical aggregate functions such as COUNT, MAX,MIN, AVERAGE and STANDARD DEVIATION are used in the queries which are called as statistical queries.

• The possibility of accessing individual information from statistical queries is reduced by following ways -

  • No statistical query is permitted whenever the number of tuples in the population specified by the selection condition falls below some threshold.

   • Prohibit sequence of queries that refer repeatedly to same population of tuples.